Detection of activated K-ras in non-small cell lung cancer by membrane array: A comparison with direct sequencing

Abstract

Abstract. The ability to detect K-ras oncogene may provide additional information for the management of patients with non-small cell lung cancer (NSCLC). In the present study, we detected the K-ras oncogene in 76 patients with NSCLC by two methods: direct sequencing of K-ras in tumor tissues and membrane array detection of the gene overexpression specific for activated K-ras in peripheral blood. The results showed that 28 (36.8%) of the 76 Taiwanese NSCLC patients had K-ras mutations, with a frequency of 36.4% (20/55) in adenocarcinomas and 38.1% (8/21) in squamous cell carcinomas. The K-ras mutations were more frequently found in smokers than in non-smokers (51.4 vs. 24.4%, P=0.015). The incidences of K-ras mutation in the subgroups of non-smokers and squamous cell carcinomas are relatively higher in Taiwan than in other countries. On the other hand, the membrane array method could positively detect circulating activated K-ras in all of the 27 NSCLC patients with K-ras mutations at codons 12, 13 and 61, and in 4 of the 48 patients with wild-type K-ras. Our results suggest that the K-ras oncogene membrane array serves as a sensitive and convenient tool for the detection of K-ras oncogene, and therefore, has a great potential for clinical applications.

A fast and convenient new technique to detect the therapeutic target, K-ras mutant, from peripheral blood in non-small cell lung cancer patients

“…A possible reason is that the mutation site of codons 18 and 31 cannot effectively activated K-ras. The same results were found in our earlier research reports [10,19]. In addition, in the paired cancer tissues of NSCLC patients tested positive for activated K-ras, no K-ras mutation has been found in 8 samples.…”

“…Of these, K-ras mutations predominate in human tumors, including those arising from the colon and lungs [8]. In our earlier research analysis of the K-ras of lung cancer, colorectal cancer, and adrenocortical cancer, the mutation rate of these cancer tissues was found to be 37%, 26%, and 45%, respectively [9][10][11][12][13][14]. The frequency of K-ras mutations across a broad range of human tumors suggests the potency of the oncogenic contribution of the constitutively active form of this protein.…”

Overexpression of EGFR pathway-related genes in the circulation is highly correlated with EGFR mutations and overexpression in paired cancer tissue from patients with non-small cell lung cancer

“…This platform of colorimetric membrane array test positively detected circulating activated K-ras in all of the NSCLC patients with K-ras mutations. Our previous results suggest that the K-ras oncogene membrane array can serve as a tool for the detection of the K-ras oncogene in the circulation (13). Activating mutations in the kinase domain of EGFR have been described in advanced NSCLC.…”

Clinical Application of Automatic Gene Chip Analyzer (WEnCA-Chipball) for Mutant Kras Detection in Peripheral Circulating Cancer Cells of Cancer Patients

“…The traditional techniques such as direct sequencing, polymerase chain reaction and restriction fragment length polymorphism are complicated and can easily be used only in tissue samples, which limits KRAS mutation detection in clinical applications. In order to improve the mutant KRAS detection efficiency, we successfully developed an Activating KRAS Detection Chip and colorimetric membrane array (CLMA) technique capable of detecting KRAS mutation status by screening circulating carcinoma cells in the surrounding bloodstream (Chen et al, 2005;Wang et al, 2006;Chong et al, 2007;Yen et al, 2009;Yang et al, 2010). However, the sensitivity still needs further improvement.…”

“…The analysis of gene overexpression has led to fundamental progress and clinical advances in the diagnosis of disease (Chen et al, 2005;Wang et al, 2006). The techniques that are commonly used to study gene overexpression include Northern blot, reverse transcriptase polymerase chain reaction (RT-PCR), and real-time PCR (Chong et al, 2007;Yen et al, 2009;Yanget al, 2009). Since Northern blot involves complex steps and a large numbers of samples, its application is limited to research instead of clinical diagnosis.…”